COMPARISON OF METHODS FOR REMOVAL OF ECTOPY IN MEASUREMENT OF HEART-RATE-VARIABILITY

Heart rate variability (HRV) analysis uses variations in heart rate to assess activity of the autonomic nervous system. Ectopic beats can af fect HRV by introducing mathematical artifact into the computations of time- and frequency-domain measures. Exclusion of ectopy-containing s egments of data from analysis has been used to correct for ectopy, but this technique eliminates data and may bias HRV measurements if ectop ic beats are causally associated with changes in autonomic tone. We ha ve assessed algorithms for correcting for ectopy: deletion, in which e ctopic beats are removed from the R-R sequence; linear and cubic splin e interpolation; and nonlinear predictive interpolation, in which ecto py-free R-R sequences are used as templates for replacing ectopic beat s. The null method (no ectopy correction) was evaluated to determine t he importance of ectopy correction. These methods were applied to comp uter-generated sequences created by adding simulated ventricular prema ture depolarizations to 5-min ectopy-free R-R sequences. The null meth od resulted in significant alterations in HRV. Deletion and nonlinear predictive interpolation performed superiorly to linear or cubic splin e interpolation, which overestimated low-frequency power and underesti mated high-frequency power. Thus ectopy correction is necessary for HR V analysis; deletion of ectopic beats performs as well as or better th an more complicated methods for these relatively short data samples.